1. Technical Field
The present invention relates to a biological information detection apparatus and the like.
2. Related Art
A biological information detection apparatus which detects biological information, such as a pulse wave of a human, is hitherto known. JP-A-2011-139725 and JP-A-2009-201919 disclose a pulsimeter of the related art which is an example of the biological information detection apparatus. The pulsimeter is put on, for example, an arm, a wrist, a finger, or the like, and detects pulsation resulting from heartbeat of a human body to measure a pulse rate.
The pulsimeter disclosed in JP-A-2011-139725 and JP-A-2009-201919 is a photoelectric pulsimeter, and a detection unit (pulse wave sensor) of the pulsimeter has a light emitting unit which emits light toward a subject (a region to be detected), and a light receiving unit which receives light (light having biological information) from the subject. In this pulsimeter, change in blood flow is detected as change in the amount of received light, thereby detecting a pulse wave. JP-A-2011-139725 discloses a pulsimeter which is put on a wrist, and JP-A-2009-201919 discloses a pulsimeter which is put on a finger.
In JP-A-2011-139725 and JP-A-2009-201919, a light transmitting member which transmits light from the light emitting unit or light from the subject is provided, and the light transmitting member has a contact surface with the subject (the skin of the wrist or the finger). Then, change in the contact state of the contact surface with the subject causes degradation of signal quality of a detection signal of the biological information, and degradation of reliability, detection precision, or the like of the biological information. If direct light from the light emitting unit enters the light receiving unit, reliability, detection precision, or the like of the biological information is further degraded.